The present disclosure relates generally to lid removal systems for cargo vessels. Cargo vessels are typically covered by one or more large heavy lids during transport to help protect the contents contained within the cargo vessel from the elements or from potential contaminants. Once the cargo vessel arrives at its final location, the lids must be removed from the cargo vessel to access and remove the contents or loading additional contents.
More particularly, this disclosure pertains to lid removal devices for cargo vessel lids which utilize an overhead crane or rigging system. One conventional solution for removing cargo vessel lids includes attaching a plurality of straps to an overhead crane or boom. The opposing ends of the straps can include hooks, each hook being attached to a corresponding location on the lid. The crane can then be used to pull the straps upward to lift and disengage the lid from the cargo vessel.
One problem with such a solution is that typically an operator is required to climb on top of the lid in order to retrieve the straps, which can be unsafe. Another problem with such a solution is that the hooks have to be attached to the lid manually, which can potentially be unsafe as well as time consuming. In one particular application of a lid removal system for a barge lid, the operator must walk around the edge of the barge in order to manually connect each hook to the lid, in addition to climbing on top of the barge lid to retrieve the straps. The barge often includes numerous obstructive objects which can be tripping hazards for operators walking around the barge to attach the hooks to the lids. If an operator loses his balance while either atop the barge lid or while walking along the edge of the barge, the operator could suffer serious injury, and could potentially fall off of the barge, which could cause serious injury or death.
Others have attempted to overcome the problems of conventional rigging by providing a strap spreader with multiple straps attached to the spreader. These solutions can potentially remove the need to climb on top of the cargo vessel lids, as the spreader can hold the straps radially outward from the crane or the rig. However, an operator must still attach the hooks manually to the lid. Additionally, the spreaders can be place under significant stress from tension and moment forces while the lids are being lifted, as the forces are being applied at the outer ends of the spreader. These stresses can cause the spreaders to wear and fatigue over time. Failure of the spreaders can cause the lids to fall during the removal operation, which can potentially cause serious injury to those nearby, as well as damage to the cargo vessel or other property.
What is needed, then, are improvements in devices for removing cargo vessel lids.